1. Field of the Invention
This invention relates to telecommunications systems. More particularly, the invention relates to an improved telephony client for mobile computing devices.
2. Description of the Related Art
Users increasingly desire to be able to make and receive telephone calls at all times. The typical methods for such access are a landline and/or a cellular telephone. A landline, however, is not always available or it can be very expensive, especially for long distance calls. A cellular telephone likewise can be expensive, depending on whether the user is in his service area, or may not be available at all, such as when traveling outside a service area or to a foreign country that employs a different cellular telephone standard.
Because of these difficulties, the use of mobile computing devices, such as laptop or notebook computers, as telephony devices is increasingly common. Such devices typically employ a telephony “soft client” to implement voice over Internet Protocol (VoIP) functionality in order to communicate by voice over a packet network, such as a local area network (LAN) or the Internet.
A disadvantage of the use of telephony soft clients is that calls may be made and received only when the entire mobile computing device is turned on. When a mobile computing device is plugged in to an electrical outlet, this may not be a problem. However, laptop or notebook computers cannot be always on because the battery only provides power for a maximum of several hours.